The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Various functional circuits, such as a delay-locked loop (DLL), a phase-locked loop, a delay circuit, and the like operate based on a pair of complementary signals. A voltage sum of the pair of complementary signals is constant. Conventionally, the pair of complementary signals is generated using an operational amplifier.